Judaism is a peoplehood before it is a creed, and the practical consequences are large: a Jew who believes nothing is still a Jew, conversion is a change of nation as much as of faith (Ruth's formula is "your people shall be my people" before "your God my God"), and the tradition has no equivalent of heresy trials for laypeople. It also means the categories other religions use fit badly — Jewish identity behaves partly like ethnicity, partly like citizenship, and partly like religion, and arguments about which dominate are internal to the community.